Characterization of Extended-Spectrum β-Lactamase-Producing Uropathogenic Escherichia coli Among Iranian Kidney Transplant Patients

Introduction: The aim of this study was to investigate the antimicrobial susceptibility pattern and the presence of ESBLs among the uropathogenic Escherichia coli (UPEC) isolated from kidney transplant patients (KTP) and community-acquired urinary tract infections (UTIs) using phenotypic and molecular methods. Materials and Methods: A total of 111 pure cultures of UPEC isolates were collected from 65 and 46 of non-KTP and KTPs with UTIs. The pattern and ESBL production of the strains were evaluated. PCR reaction to detect the presence of bla(S)(HV), bla(TEM), and bla(C)(TX-M) genes was performed. Results: The results revealed that most of UPEC isolates obtained from KTPs and control group were resistant to trimethoprim/sulfamethoxazole (84.8% vs 46.2%), while carbapenems (100% sensitivity) were the most effective against UPEC isolates. ESBL-producing strains were significantly more frequent in KTPs compared with control group (43.5% vs 23.1%, P = 0.021). The molecular results revealed that 53.2% (59/111), 45% (50/111), and 5.4% (6/111) of isolates harbored bla(C)(TX-M), bla(TEM), and bla(S)(HV) genes, respectively. Of the genes investigated, bla(CTX-M) and bla(TEM) genes were significantly higher among KTP than the control group. Conclusion: Our results showed a high proportion of multidrug-resistant and ESBL-producing isolates, which most of them harbor blaCTX-M. A significant high co-resistance to different classes of antibiotics was reported from ESBL-producing UPEC from KTPs, which remains a serious clinical challenge.